fix multicast with several network interfaces

nitroshare#18
mckaymatthew@f7a1e88

Author: Guillaume Buisson

src/src/provider.cpp

@@ -183,7 +183,7 @@ void ProviderPrivate::onMessageReceived(const Message &message)
         if (sendTxt) {
             reply.addRecord(txtRecord);
         }
-        server->sendMessage(reply);
+        server->sendMessageToAll(reply);
     }
 }
 

src/src/server.cpp

@@ -154,6 +154,13 @@ void Server::sendMessageToAll(const Message &message)
 {
     QByteArray packet;
     toPacket(message, packet);
-    d->ipv4Socket.writeDatagram(packet, MdnsIpv4Address, MdnsPort);
-    d->ipv6Socket.writeDatagram(packet, MdnsIpv6Address, MdnsPort);
+    for (const QNetworkInterface& interface : QNetworkInterface::allInterfaces()) {
+        if (interface.flags() & QNetworkInterface::CanMulticast) {
+            d->ipv4Socket.setMulticastInterface(interface);
+            d->ipv4Socket.writeDatagram(packet, MdnsIpv4Address, MdnsPort);
+
+            d->ipv6Socket.setMulticastInterface(interface);
+            d->ipv6Socket.writeDatagram(packet, MdnsIpv6Address, MdnsPort);
+        }
+    }
 }